Abstract

PROMPT CLINICAL IDENTIFICATION AND CHARACTERIZATION OF VIRULENT STREPTOCOCCUS PNEUMONIAE

Obaji U. Monday*, Oli N. Angus and Ugwu C. Malachy

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Abstract

Streptococcus pneumoniae is the leading cause of pneumonia among people with weak immune systems. Since the organism shares major biochemical characteristics with other organisms of its genetic lineage, means of prompt clinical identification is quite challenging. Colony morphology, optochin, and bile solubility tests are considered the gold standard for the biochemical identification of S. pneumoniae. However, they are time-consuming and open to contamination. Other forms of identification such as DNA-DNA hybridization, 16S rRNA, and rpoB housekeeping genes have been developed as efficient methods for identification and novel strain assignment but could be expensive and time-consuming. Urine serology offers little hope because of the possibility of the false positive test caused by the pneumococcal vaccine in immunized patients and also the presence of a pneumococcal C-polysaccharide-like compound secreted by S. mitis. The antigenic C-polysaccharide has also been detected in the urine of patients several days after treatment and recovery from the infection. For efficient discrimination between infections due to S. pneumoniae and nasopharyngeal colonization, the putative proteinase maturation protein A (PpmA) should be exploited.

Keywords: Streptococcus pneumoniae, identification, vaccine, serotype, virulence.